Owing to the development of computer technology and data compression technology in recent years, it has become possible to record image information and audio information in the form of digital signals. As a result, it is becoming possible to record television broadcasts onto a hard disk drive, a DVD-RAM or a DVD-R in the form of digital signals. Since such digital signal processing has become possible, audio-visual apparatuses (hereinafter abbreviated as AV apparatuses) are being equipped with increasing functions.
Once recorded in the form of digital signals, even if the formats of such information may be different, image information and audio information can be converted to other formats relatively easily. Therefore, in order to enhance the user's convenience, AV apparatuses of different functions are being combined, and AV apparatuses which are capable of treating image information and audio information of a number of different formats are being developed.
For example, DVD video recorders which are recently on the market incorporate a hard disk drive and a rewritable DVD drive which uses a DVD-RAM or the like, and are able to record television broadcasts to the hard disk drive or the DVD drive, or play back television broadcasts which are recorded thereon. The image information which has been recorded to the hard disk drive or the DVD drive permits searching under various conditions. Moreover, such DVD video recorders are able to play back music which is recorded on a CD or a movie which is recorded on a DVD, according to their respective standards.
Furthermore, they have a slot in which a storage medium storing images that have been recorded with a digital camera can be inserted, and/or input/output terminals to be connected to a digital video camera, so that images from the digital camera or the digital video camera can be displayed on a television set, or recorded to the hard disk drive or the DVD drive.
As the functions of an AV apparatus increases, the instructions to be given by a user to the AV apparatus in order to execute many functions will also increase. For this reason, buttons (remote control keys) corresponding to the functions will also be provided on a remote controller (remote control) for giving instructions to the AV apparatus, thus leading to an increase in the number of buttons on the remote controller.
FIG. 25 shows an example of a remote controller for a conventional DVD video recorder. The remote controller 201 includes: a group of buttons 202 for turning ON/OFF the power of a television set and the power of a DVD video recorder; a group of buttons 203 for switching between input sources of the television set; a group of buttons 204 for switching the channel of the television set; buttons 205 for adjusting the sound volume; a group of buttons 206 for switching between a hard disk drive and a DVD drive; a group of buttons 207 for performing operations such as play back or fast-forward on the drive; a group of buttons 208 for moving a cursor in order to select a function which is displayed on a television screen; and a group of buttons 209 for selecting program scheduling or a timer function.
Since so many buttons are placed on the remote controller 201, it is becoming less easy for the user to find a button that has the intended function. Since the outer shape of the remote controller 201 must be designed to a size which allows the user to hold it in one hand, it would be necessary to make each button smaller and reduce the interspaces between adjoining buttons, in order to place many buttons in the limited space of the remote controller 201. This would result in problems such as the user's difficulty to press the buttons, and likeliness to press the wrong button by mistake.